The Greener Sex

As with the European study, the most significant difference between the genders came in the transport category: Single men's driving habits have a carbon footprint of 13 metric tons of CO2e, compared with women's 9.4 tons.

After that, the most important differences, from a greenhouse gas perspective, were that single women spent more on home utilities and health care, and single men spent more on alcohol, tobacco, and education.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.